Data networks today rely heavily on shared medium, packet-based LAN technologies for both access and backbone connections. The use of packet switching systems, such as bridges and routers, to connect these LANs into global internets is now widespread. An internet router must be capable of processing packets based on many different protocols, including IP, IPX, DECNET, AppleTALK, OSI, SNA and others. The complexities of building networks capable of switching packets around the world using these different protocols is challenging to both vendors and users.
Standards-based LAN systems work reasonably well at transfer rates up to about 100 Mbps. At transfer rates above 100 Mbps, providing the processing power required by a packet switch interconnecting a group of networks becomes economically unrealistic for the performance levels desired. This inability to economically "scale up" performance is beginning to cause restrictions in some user's planned network expansions. Also, today's data networks do not provide network managers with enough control over bandwidth allocation and user access.
Tomorrow's networks are expected to support "multimedia" applications with their much greater bandwidth and real-time delivery requirements. The next generation networks should also have the ability to dynamically reconfigure the network so that it can guarantee a predetermined amount of bandwidth for the requested quality of service (QOS). This includes providing access, performance, fault tolerance and security between any specified set of end systems as directed by the network's manager. The concept is to provide network managers with complete "command and control" over the entire network's infrastructure--not just tell them when a failure has occurred.
A new set of technologies known as asynchronous transfer mode (ATM) may provide the best, long-term solution for implementing the requirements of both private and public internets. ATM promises to provide a more economical and scalable set of technologies for implementing the ultra-high-performance information networks that will be required to provide the quality of service users will demand. Thus, over the next 20 years, the network infrastructure may change from packet-based standards to one based on ATM cell switching. While changes in the accompanying network will be dramatic, it would be desirable for users making the transition to be able to retain their most recent equipment investment.
Another expected change in tomorrow's networks is a change in data flow. Data flow in today's network typically follows the client-server computing model. This is where many clients are all transferring data into and out of one or more network servers. Clients do not normally talk to each other; they share data by using the server. While this type of data exchange will continue, much more of the information flow in tomorrow's networks will be peer-to-peer. Since the ultimate goal is a truly distributed computing environment where all systems act as both the client and server, more of the data flow will follow a peer-to-peer model. The network will be required to provide more direct access to all peers wishing to use high-performance backbone internets connecting, for example, the desktop computers.
The bulk of information transported in the future will be of digital origin. This digital information will require a great deal more bandwidth than today's separate voice, fax, and SNA networks which operate with acceptable performance using voice grade telephone lines. Voice will shrink as a percentage of total traffic, while other forms of information including image and video will greatly increase. Even when compressing is available, the bandwidth requirements for both inside and outside building networks will need to be greatly expanded.
Text files and images can be sent over existing packet-based networks because the delivery of this information is not time critical. The new traffic (voice and video) is delivery time sensitive--variable or excessive latency will degrade the quality of service and can render this information worthless.
Thus, the new infrastructure requirements are expected to include:
increased workstation processing power at the desktop, which is driving the need for increased network performance and capacity; PA1 increased numbers of network users, which is driving the need for increased network security; PA1 network access and bandwidth allocation must be managed; PA1 integrated voice, video and data applications are increasing the need to be able to guarantee improved network quality of service (QOS); PA1 management must be able to provide a variable quality of service to each user based on their particular needs (a user's needs may change at any time); PA1 the ability to guarantee each user's QOS can only be achieved by tightly integrating the network and its management systems. PA1 ability to create many separate, logical work group LANs on the same physical network PA1 ability to create many separate virtual connections or circuits with a specified quality of service (QOS) PA1 ability to guarantee a requested QOS--time sensitive delivery PA1 ability to account for network use (why is the phone bill so high?) PA1 input port=2 PA1 source MAC address=00:00:1D:01:02:03 PA1 destination MAC address=00:00:1D:11:22:33;
It is an object of the present invention to provide an apparatus and method which satisfies one or more of the above-mentioned requirements.